LeetCode16——3Sum Closest

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题目链接

Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the three integers. You may assume that each input would have exactly one solution.

Example:

Given array nums = [-1, 2, 1, -4], and target = 1.

The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

代码

class Solution:
    def threeSumClosest(self, nums: 'List[int]', target: 'int') -> 'int':
        new_nums = sorted(nums)
        res = float("inf")
        for i in range(0, len(new_nums)-2):
            if i >= 1 and new_nums[i] == new_nums[i-1]:
                continue
            j = i + 1
            k = len(nums) - 1
            while j < k:
                if j >= i + 2 and new_nums[j] == new_nums[j - 1]:
                    j += 1
                    continue
                if k <len(nums) - 1 and new_nums[k] == new_nums[k + 1]:
                    k -= 1
                    continue
                if new_nums[j] + new_nums[k] + new_nums[i] == target:
                    return target
                elif new_nums[j] + new_nums[k] + new_nums[i] < target:
                    if abs(target - new_nums[j] - new_nums[k] - new_nums[i])< abs(target - res):
                        res = new_nums[j] + new_nums[k] + new_nums[i]
                    j += 1
                elif new_nums[j] + new_nums[k] + new_nums[i] > target:
                    if abs(target - new_nums[j] - new_nums[k] - new_nums[i])< abs(target - res):
                        res = new_nums[j] + new_nums[k] + new_nums[i]
                    k -= 1
        return res

其实这个代码就和3Sum那道题差不多了，稍微改动一下，衡量一下到target的距离就可以了。